Theoretical aspects of hydrogen in crystalline semiconductors

Hydrogen in semiconductors displays behavior quite different from any other impurity, causing effects which can be either beneficial or detrimental to the electronic properties. Theoretical calculations have been able to elucidate many puzzling aspects of this behavior, by providing a microscopic picture of the interactions of hydrogen with the host lattice and with other impurities. I will critically review the available theoretical techniques, and address the following topics: microscopic structure of isolated interstitial hydrogen, as well as various hydrogen-impurity complexes; electronic structure, including the relative stability of different charge states; diffusion; and H motion around impurities.